Turbo Rebuilds- need lesson

[Uwon]

I have essentially completed my build ( ) but now have not one but two leaking turbos.

http://forums.pelicanparts.com/uploads21/001+two+Turbos1345820538.jpg

The left one is k27-7006 which migrated from my crashed donor directly without any refurbishing ( it had been working well until the crash but that was back in 2009. It started leaking oil around the canister area soon after I first fired up the motor the first time.
The right one is a vanilla 3LDZ which was refurbished in about 2003-04 and was kept as a spare until I installed it as a temporary replacement to the K27. It started to leak as well.
With both turbos, the motor does not smoke, just some dripping when left standing for a few minutes.
I have pressure tested the canister, replaced the gasket and added some Curil-T and checked the hose connection leading from the canister to the scavenger pump at the front of the camshaft.
Initial questions
1. Is the leak likely because of a weak/non operating scavenger pump?
2. If it's the turbos themselves, is this a DIY job (can't find any threads on this)? Any special tools required?
Thanks in advance for any insight.
Cheers,
Johan

[Rich76_911s]

Hey Johan,

Friends with leaky turbos together, stick together!

I'm starting to think that these turbos go bad if they don't get used. Mine was also working relatively well before I started my engine build 6 months ago, but now is a leaky mess.

From what I've read here rebuilding the 3ldz and k27 are not really diy jobs. One of the problems is that good rebuild kits are very difficult to find. You can find kits on eBay, but the quality is very low and the chances of it working properly post rebuild are low.

I would probably give rarly8 or TurboKraft a call. They'll be able to give you solid advice on your turbo rebuild options. There is another place that has rebuilt them with some success but the name is escaping me at the moment.

Maybe it's time to pick a new turbo???

I'd also like to hear how to test the scavenge pump.

Good luck with it all, and the good news is that it looks like we'll both be up and running for the swap meet next year.

[T77911S]

DURABUILT is the place to go. its not that much to get it rebuilt.

you can and should test the scavenge pump.
remove the line from the catch can and put it in a jar. place the jar under the catch can and start the car. you may put a little oil the jar to start off with.
not a lot of oil comes out of the catch can but the pump should empty the jar.
I did it by myself but a helper at the key is always good.

ebay rebuild kits are crap. stay away.

[pkabush]

Sounds like it might be a s/p issue but, if you need a rebuild I'd go with Turbos Direct. They rblt my Garrett for around $350. Got the tip from Jim Fairman. Excellent service and the price cant be beat. They're in Phenix.

[Jeff NJ]

Scavenge pump rebuild is fairly straightforward. I got all the parts I needed from TurboKraft.

The basic test is to let the oil from the turbo drop into a container right below it and to put the oil line to the scavenge pump into the oil so that it sucks it out of the container. If it keeps up with the oil from the turbo outlet, it is working. However, Chris at TK told me that he tests it at low, medium and high rpm, because it may be able to keep up at idle, but not at higher rpm, which is what I think happened with mine.

I used Durabilt for my turbo rebuild. Quick service, and it works well. The VSR high speed balancer that they use is important to make sure it is properly balanced. If you don't use that, you are guessing.

[Uwon]

Thanks guys,
I will test the s/p per Jeff's suggestion and report.
Cheers,
Johan

[mrm930]

have it rebuilt by a pro. there is are details and required dimension, specs, etc. that have to happen, and diy on something like this - is not worth it.

TurboKraft also rebuilt my K27. Or just get a new one.

my .02

[Uwon]

Originally Posted by Jeff NJ

Scavenge pump rebuild is fairly straightforward. I got all the parts I needed from TurboKraft.

The basic test is to let the oil from the turbo drop into a container right below it and to put the oil line to the scavenge pump into the oil so that it sucks it out of the container. If it keeps up with the oil from the turbo outlet, it is working. However, Chris at TK told me that he tests it at low, medium and high rpm, because it may be able to keep up at idle, but not at higher rpm, which is what I think happened with mine.

Well, I did the test per Jeff's instructions and the result was hardly any sucking at idle and about 2,500 rpm.








Tomorrow I will check that the lines are not plugged and then pull the pump out. Maybe the pin has fallen out of the shaft. I wonder if the impeller can be reversed in which case I may have done this. Looking at the second pic, it is also possible to instal the pump in my case by turning it 180 degrees as my exhaust is a flex hose (not hard line per the 930) leading directly into the oil tank. Anyone have any other ideas?
Cheers,
Johan

[Jeff NJ]

Below is a pic of my scavenge pump taken apart. Simple to rebuild. Contact Chris at turbokraft and he will send you the rebuild kit.

[Rawknees'Turbo]

Johan, your pump is on upside down (180 degrees out - just as you wondered about), and that is precisely why it is not doing any sucking (totally opposite to Paul - he can do that upside down, right side up, and sideways!!!). And you are not alone in having done this - the esteemed, and sorely missed, Norm K. did the same thing and got the same results.

[JFairman]

You could put a new ball bearing Garret turbo on with the correct oil restrictor and forget about the smoke with the side effect of more horsepower and less turbo lag.
Chris at Turbokraft can set you up with the right one.

[Rich76_911s]

How is the scavenge pump on backwards???


Here is mine before being pulled off the engine.




Is mine on backwards too??

[Uwon]

Hey Rich,
I agree with you. I just found a pic of my motor pre-rebuild and the pump is positioned like yours. Thanks for confirming this. The mistery continues. Just going to the garage now.
Johan

[Rawknees'Turbo]

Turns out that I am either dumb, blind or both - looked again at mine (car is in the air right now), and youse two choads' are the same as mine. Sorry for the dumbassery on my part!

Johan, another thing that can prevent suckage by the scavenge pump is if the oil line/pipe between the turbocharger drip tank and the scavenge pump has a pin hole in it - pump then primarily sucks air and very little oil . . . difficult to spot because you can have a pinhole that doesn't even leak much, if any oil (top of pipe, not much oil passing through it, etc.).

[Uwon]

RawKnees, no worries.
Blew air thru pipe to S/P and hose to tank. No obstructions.
Bench tested pump with oil. Sucked nicely when turning by hand. Really well when turned with drill...


I'm suspicious that the two cap bolts at the end of the camshaft are not tall enough to to constantly hit the cross pin on the end of the pump shaft.





More tomorrow.
Johan

[Jeff NJ]

Unless someone has messed with the those bolts, I don't see how it's possible to not hit the pin. At least on mine it wasn't possible...
If the pump sucks correctly when apart, but not when hooked up to the oil pipe, then maybe there is a pinhole or loose connection letting air in between the oil tank and the pump?

[JFairman]

I read somewhere the 930 turbo scavange pump uses the gears from a VW bug engine oil pump.
Don't know if it's true.

[Uwon]

Originally Posted by Jeff NJ

Unless someone has messed with the those bolts, I don't see how it's possible to not hit the pin. At least on mine it wasn't possible...
If the pump sucks correctly when apart, but not when hooked up to the oil pipe, then maybe there is a pinhole or loose connection letting air in between the oil tank and the pump?

Jeff, I rebuilt the whole motor with all new hardware. I'm guessing that my new cap bolt heads are not as high as the original ones. I may have to add washers. We'll see.
If there were pin holes I would have had an oil leak by now. Motor is dry save the bottom of the turbo.
Johan

[Uwon]

Raised the cap bolt heads with a couple of washers each and the pump now empties the canister nicely at idle and 3,500 rpm. Bolts still have plenty of thread left. Now the question remains whether it will solve the turbo drip. I'll find out soon enough.
Johan

[Jeff NJ]

Good news on finding the issue. Hopefully the turbo seals aren't totally blown and you are all good!